| Pigment power: Vivid colors of fruit, vegetables promise rainbow of benefits by Bob Condor-Chicago Tribune Most mornings, Jim Joseph tosses a handful of blueberries into a soy-protein smoothie as part of his breakfast. Then he commutes to his laboratory at Tufts University near Boston and breaks out more blueberries. This time, he feeds the berries to rats as part of ongoing experiments about the nutrients in fruit and vegetables. What Joseph and other researchers are finding has surprised even them. Mostly known for filling pies or dotting muffins, the petite blueberry is gaining a reputation as one of nature's nutritional heavyweights. Joseph conducted an experiment showing blueberries can effectively protect against age-related memory loss and diminished motor skills in lab rats, a feat unmatched by even spinach in his experiments. "What struck me was the ability to change motor behavior" for the better, said Joseph, chief of the neuroscience lab at the U.S. Department of Agriculture Human Nutrition Research Center at Tufts. "There is virtually nothing out there that can change motor behavior in aging." His Tufts colleague Ronald Prior rated 60 fruits and vegetables for potency of antioxidants, which keep cells normal and fight cancer, heart disease and other degenerative conditions. Blueberries topped the list. The Tufts results appear to be part of a grander color scheme for getting your daily nutrients - and showing us that we might be missing the point about getting our five servings of fruit and vegetables. Five servings of pigment might be more like it: Get your blues, reds, purples, oranges and yellows along with your greens. "The substances that give pigments to fruits and vegetables were discovered and named long ago," said Phyllis Bowen, associate professor of human nutrition and dietetics at the University of Illinois-Chicago. "But it's been a revelation to all of us in the last few years that the pigments can be so beneficial to your health and well-being. The research is building." For instance, strawberries, prunes, black currants and boysenberries also rated high on the Tufts test for antioxidant strength. A similar analysis by German researchers gave high marks to beets, too often an afterthought at the salad bar. One caveat: Bowen said water-soluble antioxidants in berries and other produce are believed to show up more readily than fat-soluble antioxidants during such analyses. A Michigan State University study showed that sour cherries provide 10 times the anti-inflammatory relief of aspirin and don't irritate the stomach. Other university researchers have documented the protective value of pale yellow and orange produce for macular degeneration, a debilitating vision condition that can lead to blindness. What's more, carrots, long associated by folklore (and science) with improved eyesight, have also been linked to reduced cholesterol and risk of stroke. The reported health benefits of green tea and red wine (and purple grapes) have gotten much publicity. Same for the tomatoes in your favorite spaghetti sauce or ketchup. Score more points for Pigment Power. Any colorful fruit or vegetable (skin or interior, provided you eat it all) contains phytochemicals. These antioxidant substances fight cancer, heart disease and other illnesses by neutralizing "free radicals," which if left unchallenged can destroy or "oxidize" healthy cells. Many of these natural antioxidants also have anti-inflammatory properties, and some naturally reduce blood cholesterol. Each of nature's food hues has its own bundle of pigment-related phytonutrients, which are broadly sorted into such categories as polyphenols, flavonoids and carotenoids. The categories do overlap. Polyphenols are plentiful in the deeper-colored plant foods such as blueberries, strawberries, grapes, green tea and, happily, chocolate. Flavonoids can also be found in the newfound champion blueberries, along with cranberries, currants, teas and olives. Carotenoids are responsible for the oranges and yellows in such foods as cantaloupe, mangoes, carrots, sweet potatoes and pink grapefruit. Another class of carotenoids are in red foods, such as tomatoes and watermelon. The most famous carotenoid, beta carotene, which helps the body make vitamin A, is just one carotene among hundreds. Other individual pigment substances have been singled out, such as lycopene in tomatoes or lutein in peas, carrots and squashes. Almost everyone knows that chlorophyll is the pigment in green vegetables and leaves. One term you will be hearing more of is anthocyanin, the natural dye and nutrient that gives blue and purple color to blueberries, plums and cherries. Joseph, of Tufts, is applying for a grant to identify which of four polyphenol families in blueberries, including anthocyanins, are most responsible for the anti-aging effects. The study will take two to three years. The strategy appears to have worked already with widely publicized research about cooked tomatoes and lycopene, which found that carotenoids are more available to the body if cooked slightly. Men are getting the message that multiple weekly servings of tomato sauce or soups can reduce risk for prostate troubles. Bowen just completed the first phase of a clinical trial at UIC that reduced prostate-specific antigen levels in men awaiting radical prostatectomy surgery by 18 percent in three weeks. The African-American subjects - a high-risk group for prostate cancer - benefited by eating three-quarters cup of tomato sauce with pasta each day. "We are starting to see that oxidative stress is a huge factor in aging diseases," Bowen said, referring to the damage caused by free radicals. "Eating antioxidants in plant foods can hold off the damage. The deeper the pigment, the better for you." |
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